quantum computer

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quantum computer

[′kwän·təm kəm¦pyüd·ər]
(computer science)
A computer in which the time evolution of the state of the individual switching elements of the computer is governed by the laws of quantum mechanics.

quantum computer

(computer)
A type of computer which uses the ability of quantum systems, such as a collection of atoms, to be in many different states at once. In theory, such superpositions allow the computer to perform many different computations simultaneously. This capability is combined with interference among the states to produce answers to some problems, such as factoring integers, much more rapidly than is possible with conventional computers. In practice, such machines have not yet been built due to their extreme sensitivity to noise.

Oxford University, Stanford University.

A quantum search algorithm for constraint satisfaction problems exhibits the phase transition for NP-complete problems.
References in periodicals archive ?
Fortunately, Bernstein has conjectured in [14] that only some schemes can be reduced to computational problems on lattices, which are still hard even for quantum algorithms.
The first example is the experimental demonstration of quantum algorithms using a single photon and linear optics.
In this new model, a desired quantum algorithm can be implemented by letting the qubits "quantum walk" on an appropriately chosen graph, without having to control the qubits.
Keywords: qubit, quantum algorithm, classical computing, quantum computing
In other words, the result only showed that the quantum algorithm for prime factorization could be simulated using classical computing.
Therefore, because the quantum algorithm for the knapsack problem is examined this time, its result is reported.
This observation turns out to be the first quantum algorithm, known as the Deutseh-Josza algorithm (Deutsch & Jozsa, 1992), where physical principles such as quantum interference and quantum entanglement were made evident as a powerful computational resource.
A quantum algorithm with polynomial time for factorization has already been discovered [1], so if quantum computers become a reality, RSA and other public-key cryptosystems would become obsolete.
It wasn't until 1994, when Peter Shor surprised the world by describing a polynomial time quantum algorithm for factoring integers [Shor 1994; 1997], that the field of quantum computing came into its own.
This article is not simply about re-presenting a known result about Grover's algorithm; it also aims to demonstrate that the probabilistic wp-calculus is suitable for both modeling and reasoning about a quantum algorithm.
All of these variables make it difficult for a programmer to build a quantum algorithm that can achieve something useful without errors and before it reverts to a classical state, but that doesn't take away from just how far researchers have come in recent years, and how big today's announcement is in the quantum computing world.